Impact of Fertilizers on Greenhouse Gas Mitigating Microbes in Agroecosystem

Fertilizers have become an essential part of our global food supply chain, necessary to sustain our growing population. The excessive use of synthetic fertilizers is the biggest culprit, featuring mainly in the United States, India, Europe, and China. The production and use of synthetic nitrogen contribute significantly to greenhouse gas (GHG) emissions. Excessively applied fertilizers, especially nitrogen, lead to microbial reactions that generate the greenhouse gas known as N2O. Methane, with high global warming potential and an atmospheric concentration of 1.7 μmol mol−1, is currently responsible for 16% of the global warming. The GHGs Viz., carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are byproducts of the survival of the microorganisms living in soil, manure, or animal enteric systems. Soils play an important role in the CH4 cycle, with methanotrophy and methanogenesis taking place in them. Methanogens produce methane as the major end product of their metabolism in a unique energy-generating process. Methanotrophs, play a vital role in lowering methane levels in the atmosphere under certain environmental conditions and factors. Lactic acid bacteria that can reduce methane emissions from livestock farming and are essential for ensuring sustainable food production in the future and sulphate-reducing microbes, which participate in methanogenic degradation pathways, also lower methane emissions. Utilizing practices like minimizing fertilizer usage and incorporating waste into agricultural production processes can mitigate greenhouse gas emissions into the atmosphere. Additionally, organic fertilizer application has been shown to improve ecosystem carbon balance and reduce the GHG balance; manure application is the best way to increase soil carbon and to decrease GHG emissions by reducing the methanogen activity.